Changes in tissue sodium concentration and sodium relaxation times during the maturation of human knee cartilage: Ex vivo 23 Na MRI study at 10.5 T.

PURPOSE: To evaluate the influence of skeletal maturation on sodium (23 Na) MRI relaxation parameters and the accuracy of tissue sodium concentration (TSC) quantification in human knee cartilage. METHODS: Twelve pediatric knee specimens were imaged with whole-body 10.5 T MRI using a density-adapted 3D radial projection sequence to evaluate 23 Na parameters: B1 + , T1 , biexponential T 2 * $$ {\mathrm{T}}_2^{\ast } $$ , and TSC. Water, collagen, and sulfated glycosaminoglycan (sGAG) content were calculated from osteochondral biopsies. The TSC was corrected for B1 + , relaxation, and water content. The literature-based TSC (TSCLB ) used previously published values for corrections, whereas the specimen-specific TSC (TSCSP ) used measurements from individual specimens. 23 Na parameters were evaluated in eight cartilage compartments segmented on proton images. Associations between 23 Na parameters, TSCLB - TSCSP difference, biochemical content, and age were determined. RESULTS: From birth to 12 years, cartilage water content decreased by 18%; collagen increased by 59%; and sGAG decreased by 36% (all R2 ≥ 0.557). The short T 2 * $$ {\mathrm{T}}_2^{\ast } $$ ( T 2 * S $$ {{\mathrm{T}}_2^{\ast}}_{\mathrm{S}} $$ ) decreased by 72%, and the signal fraction relaxing with T 2 * S $$ {{\mathrm{T}}_2^{\ast}}_{\mathrm{S}} $$ ( fT 2 * S $$ {{\mathrm{fT}}_2^{\ast}}_{\mathrm{S}} $$ ) increased by 55% during the first 5 years but remained relatively stable after that. TSCSP was significantly correlated with sGAG content from biopsies (R2 = 0.739). Depending on age, TSCLB showed higher or lower values than TSCSP . The TSCLB - TSCSP difference was significantly correlated with T 2 * S $$ {{\mathrm{T}}_2^{\ast}}_{\mathrm{S}} $$ (R2 = 0.850), fT 2 * S $$ {{\mathrm{fT}}_2^{\ast}}_{\mathrm{S}} $$ (R2 = 0.651), and water content (R2 = 0.738). CONCLUSION: TSC and relaxation parameters measured with 23 Na MRI provide noninvasive information about changes in sGAG content and collagen matrix during cartilage maturation. Cartilage TSC quantification assuming fixed relaxation may be feasible in children older than 5 years.

MRI of patellar stabilizers: Anatomic visibility, inter-reader reliability, and intra-reader reproducibility of primary and secondary ligament anatomy.

OBJECTIVE: To compare MRI features of medial and lateral patellar stabilizers in patients with and without patellar instability. METHODS: Retrospective study of 196 patients (mean age, 33.1 ± 18.5 years; 119 women) after diagnosis of patellar instability (cohort-1, acute patellar dislocation; cohort-2, chronic patellar maltracking) or no patellar instability (cohort-3, acute ACL rupture; cohort-4, chronic medial meniscus tear). On MRI, four medial and four lateral stabilizers were evaluated for visibility and injury by three readers independently. Inter- and intra-reader agreement was determined. RESULTS: Medial and lateral patellofemoral ligaments (MPFL and LPFL) were mostly or fully visualized in all cases (100%). Of the secondary patellar stabilizers, the medial patellotibial ligament was mostly or fully visualized in 166 cases (84.7%). Other secondary stabilizers were mostly or fully visualized in only a minority of cases (range, 0.5-32.1%). Injury scores for all four medial stabilizers were higher in patients with acute patellar dislocation than the other 3 cohorts (p < .05). Visibility inter- and intra-reader agreement was good for medial stabilizers (κ 0.61-0.78) and moderate-to-good for lateral stabilizers (κ 0.40-0.72). Injury inter- and intra-reader agreement was moderate-to-excellent for medial stabilizers (κ 0.43-0.90) and poor-to-moderate for lateral stabilizers (κ 0-0.50). CONCLUSION: The MPFL and LPFL were well visualized on MRI while the secondary stabilizers were less frequently visualized. The secondary stabilizers were more frequently visualized medially than laterally, and patellotibial ligaments were more frequently visualized compared to the other secondary stabilizers. Injury to the medial stabilizers was more common with acute patellar dislocation than with chronic patellar maltracking or other knee injuries.

Patella and Trochlea Osteochondritis Dissecans: Demographics and Treatment Paradigms.

OBJECTIVE: Previous research on patellar and trochlear groove osteochondritis dissecans (OCD) is limited by small sample sizes. This study aims to describe the presentation of patients with OCD lesions of the patella and trochlea and characterize the outcomes of operative and nonoperative treatments. METHODS: This retrospective cohort study identified all patients from a single institution from 2008 to 2021 with patellar and/or trochlear OCD lesions. Patients were excluded from the study if surgical records were unavailable or if the patient had knee surgery for a different injury at index surgery or in the 12 months postoperative. Minimum follow-up was 12 months. Outcomes included a return to sports (RTS), pain resolution, radiographic healing, and treatment "success" (defined as full RTS, complete pain resolution, and full healing on imaging). RESULTS: A total of 68 patients (75 knees) were included-45 (60%) with patellar OCD and 30 (40%) with trochlear. Of the patients, 69% were males. The median age at knee OCD diagnosis was 14 years. At the final follow-up, 62% of knees (n = 44) recovered sufficiently to allow a full RTS and 54% of knees (n = 39) had full pain resolution. Of the 46 knees with radiographic imaging at least 1 year apart, 63% had full healing of the lesion. There was no significant difference in RTS, pain resolution, radiographic healing, or overall success when comparing treatments. CONCLUSIONS: This study provides valuable epidemiologic demographic and outcome data regarding the scarcely reported patellar and trochlear OCD. While over half of patients fully returned to sports and reported full pain resolution, a large proportion continued to experience symptoms over a year after presentation. Future research should aim to better define the treatment algorithms for these OCD subtypes. LEVEL OF EVIDENCE: Level III.

Consensus-Based Guidelines for Management of First-Time Patellar Dislocation in Adolescents.

BACKGROUND: The management of first-time patellar dislocation remains variable, with limited evidence to support or compare different operative and nonoperative modalities. The primary aim was to establish consensus-based guidelines for different components of nonoperative treatment following a first-time patellar dislocation. The secondary aim was to develop guidelines related to management after failed nonoperative treatment. The tertiary aim was to establish consensus-based guidelines for the management of first-time patellar dislocation with a concomitant osteochondral fracture. METHODS: A 29-question, multiple-choice, case-based survey was developed by 20 members of the Patellofemoral Research Interest Group of the Pediatric Research in Sports Medicine Society. The survey consisted of questions related to demographic information, management of first-time patellar dislocation without an osteochondral fracture, and management of first-time patellar dislocation with a 2 cm osteochondral fracture. The survey underwent 2 rounds of iterations by Patellofemoral Research Interest Group members and the final survey was administered to Pediatric Research in Sports Medicine members, using REDCap. Consensus-based guidelines were generated when more than 66% of respondents chose the same answer. RESULTS: Seventy-nine of 157 (50%) eligible members responded. Sixty-one were orthopaedic surgeons and 18 were primary sports medicine physicians. Eleven consensus-based guidelines were generated based on survey responses. Those that met the criteria for consensus included initial knee radiographs (99% consensus), nonoperative treatment for first-time patellar dislocation without an osteochondral fracture (99%), physical therapy starting within the first month postinjury (99%), with return to sport after 2 to 4 months (68%) with a brace (75%) and further follow-up as needed (75%). Surgical treatment was recommended if there were patellar subluxation episodes after 6 months of nonoperative treatment (84%). Patellar stabilization should be considered for a first-time dislocation with an osteochondral fracture (81.5%). CONCLUSION: Consensus-based guidelines offer recommendations for the management of first-time patellar dislocation with or without an osteochondral fracture. Several changing trends and areas of disagreement were noted in clinical practice. CLINICAL RELEVANCE: In the absence of high-level evidence, consensus-based guidelines may aid in clinical decision-making when treating patients following a first-time patellar dislocation. These guidelines highlight the evolving trends in clinical practice for the management of first-time patellar dislocation. Areas not reaching consensus serve as topics for future research.

Knee MRI: Meniscus Roots, Ramps, Repairs, and Repercussions.

Menisci play an essential role in maintaining normal pain-free function of the knee. While there are decades of MRI literature on the tears involving the meniscus body and horns, there is now a surge in knowledge regarding injuries at the meniscus roots and periphery. The authors briefly highlight new insights into meniscus anatomy and then summarize recent developments in the understanding of meniscus injuries that matter, emphasizing meniscus injuries at the root and peripheral (eg, ramp) regions that may be missed easily at MRI and arthroscopy. Root and ramp tears are important to diagnose because they may be amenable to repair. However, if these tears are left untreated, ongoing pain and accelerated cartilage degeneration may ensue. The posterior roots of the medial and lateral menisci are most commonly affected by injury, and each of these injuries is associated with distinctive clinical profiles, MRI findings, and tear patterns. Specific diagnostic pitfalls can make the roots challenging to evaluate, including MRI artifacts and anatomic variations. As with root tears, MRI interpretation and orthopedic treatment have important differences for injuries at the medial versus lateral meniscus (LM) periphery (located at or near the meniscocapsular junction). Medially, ramp lesions typically occur in the setting of an anterior cruciate ligament rupture and are generally classified into five patterns. Laterally, the meniscocapsular junction may be injured in association with tibial plateau fractures, but disruption of the popliteomeniscal fascicles may also result in a hypermobile LM. Updated knowledge of the meniscus root and ramp tears is crucial in optimizing diagnostic imaging before repair and understanding the clinical repercussions. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available in the Online Learning Center.

Patellar Tracking: An Old Problem with New Insights.

Patellofemoral pain and instability are common indications for imaging that are encountered in everyday practice. The authors comprehensively review key aspects of patellofemoral instability pertinent to radiologists that can be seen before the onset of osteoarthritis, highlighting the anatomy, clinical evaluation, diagnostic imaging, and treatment. Regarding the anatomy, the medial patellofemoral ligament (MPFL) is the primary static soft-tissue restraint to lateral patellar displacement and is commonly reconstructed surgically in patients with MPFL dysfunction and patellar instability. Osteoarticular abnormalities that predispose individuals to patellar instability include patellar malalignment, trochlear dysplasia, and tibial tubercle lateralization. Clinically, patients with patellar instability may be divided into two broad groups with imaging findings that sometimes overlap: patients with a history of overt patellar instability after a traumatic event (eg, dislocation, subluxation) and patients without such a history. In terms of imaging, radiography is generally the initial examination of choice, and MRI is the most common cross-sectional examination performed preoperatively. For all imaging techniques, there has been a proliferation of published radiologic measurement methods. The authors summarize the most common validated measurements for patellar malalignment, trochlear dysplasia, and tibial tubercle lateralization. Given that static imaging is inherently limited in the evaluation of patellar motion, dynamic imaging with US, CT, or MRI may be requested by some surgeons. The primary treatment strategy for patellofemoral pain is conservative. Surgical treatment options include MPFL reconstruction with or without osseous corrections such as trochleoplasty and tibial tubercle osteotomy. Postoperative complications evaluated at imaging include patellar fracture, graft failure, graft malposition, and medial patellar subluxation. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Pediatric meniscus morphology varies with age: a cadaveric study.

PURPOSE: In adolescent patients, meniscal tear injury can occur either in isolation (e.g., discoid lateral meniscus tears) or in association with other traumatic injuries including tibial eminence fracture or ACL tear. Damage to meniscal integrity has been shown to increase contact pressure in articular cartilage, increasing risk of early onset osteoarthritis. In symptomatic patients failing conservative management, surgical intervention via meniscus repair or meniscus transplant is indicated. The purpose of this study was to evaluate the radial dimensions of pediatric menisci throughout development. The hypothesis was that the average radial meniscus dimensions will increase as specimen age increases, and mean medial and lateral region measurements will increase at a linear rate. METHODS: Seventy-eight skeletally immature knee cadaver specimens under age 12 years were included in this study. The meniscal specimens were photographed in the axial view with ruler in the plane of the tibial plateau and analyzed using computer-aided design (CAD) software (Autodesk Fusion 360). Measurements were taken from inner to outer meniscus rims at five 45 degree intervals using the clockface as a reference (12:00, 1:30, 3:00, 4:30, 6:00), and total area of meniscus and tibial plateau was recorded. Generalized linear models were used to evaluate the associations of radial width measurements with age, tibial coverage, and lateral vs. medial meniscus widths. RESULTS: All radial width measurements increased significantly with specimen age (p ≤ 0.002), and all lateral-medial meniscal widths increased (p < 0.001). The anterior zones of the meniscus were found to increase at the slowest rate compared to other regions. Tibial plateau coverage was found to not significantly vary with age. CONCLUSIONS: Meniscus radial width and lateral-medial meniscus width are related to age. The anterior width of the meniscus varied least with age. Improved anatomic understanding may help surgeons more effectively plan for meniscus repair, discoid resection/saucerization/repair, and also support appropriate selection of meniscus allograft for transplantation.

Evaluating the Readability and Quality of Online Patient Education Materials for Pediatric ACL Tears.

BACKGROUND: As the rate of anterior cruciate ligament (ACL) tears increases in children, the internet has become a major source of information and education. In the United States, the average adult reads at about an eighth grade level. The National Institutes of Health recommends that patient education materials do not exceed a sixth-grade reading level. Therefore, the most accessed resources on the internet should be created with this in mind. The purpose of this study is to assess the readability and quality of online patient resources for pediatric ACL tears. METHODS: Google was queried using the term "Pediatric ACL Tear" on May 26, 2022. The most popular sites were identified through page one of a Google search. All content was evaluated to assure information was directed toward patients. To determine reading difficulty, the most widely accepted readability tests: Flesch Reading Ease Index, Flesch-Kincaid Grade Level, and Gunning Fog Index were calculated through plain text in Microsoft Word and URL in online readability checker Readable.io. RESULTS: The average grade level for all resources was above the recommended reading level based on both Microsoft Word and Readable.io calculations. Each source exceeded the NIH recommendation by 2.6 grade levels on average (Mean grade level readability was 8.6 ± 1.9). Four of the 6 sites were above the average US reading level, exceeding the eighth grade by an average of 1.5 grade levels. All 6 sites analyzed had a mean DISCERN score of 61.9, meeting the 'good quality' criteria. CONCLUSION: The most readily available online materials for Pediatric ACL tears were of 'good quality' but above both the NIH-recommended readability level and the average US adult reading level. With the increasing need for treatment of ACL tears in pediatric and adolescent patients and greater internet accessibility in these populations, it is important to consider the readability of these resources in support of increased health literacy and improved outcomes. CLINICAL RELEVANCE: It is important for physicians treating young patients with ACL tears to be aware of all sources of information and support, including content shared online as these platforms are increasingly utilized, especially by patients and families of lower socioeconomic status.

Intrarater and Interrater Reliability of Radiographic Characteristics in Skeletally Immature Patients With Anterior Cruciate Ligament Tears: A PLUTO Study Group Reliability Study.

BACKGROUND: Radiographic measurements of limb alignment in skeletally immature patients with anterior cruciate ligament (ACL) tears are frequently used for surgical decision-making, preoperative planning, and postoperative monitoring of skeletal growth. However, the interrater and intrarater reliability of these radiographic characteristics in this patient population is not well documented. HYPOTHESIS: Excellent reliability across 4 raters will be demonstrated for all digital measures of length, coronal plane joint orientation angles, mechanical axis, and tibial slope in skeletally immature patients with ACL tears. STUDY DESIGN: Cohort study (diagnosis). METHODS: Three fellowship-trained orthopaedic surgeons and 1 medical student performed 2 rounds of radiographic measurements on digital imaging (lateral knee radiographs and long-leg radiographs) of skeletally immature patients with ACL tears. Intrarater and interrater reliability for continuous radiographic measurements was assessed with intraclass correlation coefficients (ICCs) across 4 raters with 95% CIs for affected and unaffected side measurements. Interrater reliability analysis used an ICC (2, 4) structure and intrarater reliability analysis used an ICC (2, 1) structure. A weighted kappa coefficient was calculated for ordinal variables along with 95% CIs for both interrater and intrarater reliability. Agreement statistic interpretations are based on scales described by Fleiss, and Cicchetti and Sparrow: <0.40, poor; 0.40 to 0.59, fair; 0.60 to 0.74, good; and >0.74, excellent. RESULTS: Radiographs from a convenience sample of 43 patients were included. Intrarater reliability was excellent for nearly all measurements and raters. Interrater reliability was also excellent for nearly all reads for all measurements. CONCLUSION: Radiographic reliability of long-leg radiographs and lateral knee x-rays in skeletally immature children with ACL tears is excellent across nearly all measures and raters and can be obtained and interpreted as reliable and reproducible means to measure limb length and alignment. LEVEL OF EVIDENCE: Level III.

Developmental Dysplasia of the Hip: An Examination of Care Practices of Pediatricians.

OBJECTIVE: To evaluate the decision making processes of pediatricians regarding diagnosis and management of developmental dysplasia of the hip (DDH) by conducting a survey of pediatricians in the United States. STUDY DESIGN: An electronic survey was sent to multiple American Academy of Pediatrics state chapters and academic pediatrics groups, and responses were received from pediatricians in 10 states. The survey included demographics, guideline use, clinical scenarios, and referrals/imaging practices. The number of responses to each survey question and their relative frequencies were calculated. RESULTS: We received 139 responses and included 126 in our analyses. Only 50% of the responding pediatricians (63 of 126) practiced in an institution that endorses a care pathway for DDH. Only 5.6% of the pediatricians (7 of 125) have referred patients at 12-18 months between diagnosis and management to a specialist for suspected DDH, and 9.5% (12 of 125) have referred patients between 6 and 9 months. Almost one-quarter of the pediatricians (23%; 29 of 126) cited "hip click" as an abnormality that would prompt them to refer a patient to a specialist, and 72.2% (91 of 126) indicated that family history of DDH warrants an ultrasound regardless of the physical examination findings. Moreover, 10.3% of the surveyed pediatricians (13 of 126) reported being only "somewhat" or "moderately" familiar with the Barlow and Ortolani maneuvers. CONCLUSIONS: The results of this study indicate that there is an opportunity to better distribute and implement DDH guidelines. The large number of pediatrician respondents who would not refer patients to a specialist or order imaging studies appropriately represents an opportunity for education. The implementation of a care map with standard referral and imaging practices could improve the care of patients with DDH.

Computational Study of the Gas-Phase Thermal Degradation of Perfluoroalkyl Carboxylic Acids.

Perfluoroalkyl carboxylic acids (PFCAs) are persistent and ubiquitous pollutants. Environmental remediation is often achieved by absorption on matrices followed by high-temperature thermal treatment to desorb and decompose the PFCAs. Detailed product studies of the thermal degradation of PFCAs have been hampered by the complex nature of product mixtures and associated analytical challenges. On the basis of high-level computational studies, we propose reaction pathways and mechanisms for the high-temperature mineralization of a series of linear PFCAs with a backbone length from C-4 to C-8. The favored initial reaction pathways are nonselective C-C bond homolytic cleavages (with bond dissociation energies of ∼75-90 kcal/mol), resulting in carbon-centered radicals which can undergo ß-scissions (Ea ≈ 30-40 kcal/mol) which can be preceded by F atom shifts (Ea ≈ 30-45 kcal/mol). In competing barrierless processes, the carbon-centered radicals can lose •F, resulting in the formation of volatile perfluoroalkenes (ΔH ≈ 50-80 kcal/mol). A variety of competing fragmentation processes yield shorter chain perfluorinated PFCAs, isomeric alkenes, alkenoic acids, alkyl, and alkyloic acid radicals. The results provide the energetics for primary, secondary, and tertiary reaction products and insight into the fundamental understanding of the pyrolytic pathways of PFCAs leading to their mineralization.

Evaluating Information About Osteochondritis Dissecans Shared Across Social Media Platforms.

BACKGROUND: With the rise of social media, patients are using a variety of online resources to gather information about medical conditions and connect with others for support. Osteochondritis dissecans (OCD) occurs most commonly among children and adolescents, necessitating early diagnosis and management. The purpose of this study is to evaluate content on social media about OCD to quantify the reach of information shared and themes of discussion surrounding this condition. METHODS: A search was performed across Facebook, Instagram, YouTube, and TikTok using the term "osteochondritis dissecans" to identify information shared related to this topic which was then analyzed based on engagement using number of followers, posts, and/or views. RESULTS: Facebook groups provided a forum for online support and information sharing among patients with OCD and their families. The 4 identified groups had a cumulative following of over 4000 people with posts that shared personal recovery stories, solicited treatment advice, and provided updates on patient progress. Review of related Instagram hashtags revealed over 4500 posts, many of which shared personal accounts of living with OCD. The top 5 most viewed YouTube videos collectively had over 189,000 views and were focused on educational information about OCD, relevant surgical techniques, and pertinent anatomy. The top 3 OCD-related TikTok hashtags had over 4 million total views centered on factual knowledge and sharing changes before and after surgical treatment. CONCLUSION: Patients with OCD and their families seek information about their condition and treatment on online sources including social media. Although social media provides a supportive community to share and receive advice, the quality of information shared in these groups is a subject for concern. Increasing physician involvement and awareness of the information shared across social media platforms may improve accuracy of information and content available to patients. CLINICAL RELEVANCE: It is important for physicians treating patients with OCD to be aware of all sources of information and support, including content shared on social media as these platforms allow for the sharing of personal stories, recommendations for treatment, and educational content.

Quality Measures for Pediatric Orthopaedic Surgery: A Systematic Review.

BACKGROUND: Quality measures provide a way to assess health care delivery and to identify areas for improvement that can inform patient care delivery. When operationalized by a hospital or a payer, quality measures can also be tied to physician or hospital reimbursement. Prior work on quality measures in orthopaedic surgery have identified substantial gaps in measurement portfolios and have highlighted areas for future measure development. This study aims to identify the portfolio of quality measures in pediatric orthopaedic surgery. METHODS: We used methodology of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and reviewed PubMed/ MEDLINE and EMBASE, the American Academy of Orthopaedic Surgery (AAOS), National Quality Forum (NQF), and the Agency for Healthcare Research and Quality (AHRQ), for quality measures and candidate quality measures. Quality measure and candidate quality measures were categorized as structure, process, or outcome. Measures were also classified into 1 of the 6 National Quality Strategy priorities (safety, effective, patient centered, timely, efficient, and equitable). RESULTS: A review of PubMed/EMBASE returned 1640 potential quality measures and articles. A review of AAOS, NQF, and AHRQ databases found 80 potential quality measures. After screening we found a total of 18 quality measures and candidate quality measures specifically for pediatric orthopaedic surgery. Quality measures addressed conditions such as supracondylar humerus fractures, developmental dysplasia of the hip, and osteochondritis dissecans. There were 10 process measures, 8 outcome measure, and 0 structure measures. When we categorized by National Quality Strategy priorities and found 50% (9/18) were effective clinical care, 44% (8/18) were person and care-giver centered experience and outcomes, 6% (1/18) were efficient use of resources. CONCLUSIONS: There are few quality measures and candidate quality measures to assess pediatric orthopaedic surgery. Of the quality measure available, process measures are relatively over-represented. Pediatric orthopaedic surgeons can lead the development of outcome (eg, patient-reported outcomes after surgery) and structure measures (eg, subspecialty training certification) to assess quality of care in pediatric orthopaedic surgery. LEVEL OF EVIDENCE: Level II-systematic review.

What's New in the Management of Pediatric Anterior Cruciate Ligament Tears and Tibial Spine Fractures.

As the number of pediatric and adolescent patients participating in sports continues to increase, so too does the incidence of anterior cruciate ligament (ACL) tears in this population. There is increasing research on pediatric and adolescent ACL tears; hundreds of articles on the topic have been published in the past few years alone. It is important to highlight the most pertinent information in the past decade. In discussing pediatric ACL tears, it is also important to review tibial spine fractures. These injuries are rightfully grouped together because tibial spine fractures often occur with a mechanism of injury similar to that of ACL tears, but typically in a younger age group. Because management is different, understanding the similarities and differences between the two pathologies is important. Recent updates on the epidemiology, diagnosis, management, and outcomes of both pediatric ACL tears and tibial spine fractures need to be reviewed.

What's New in Osteochondritis Dissecans of the Knee, Elbow, and Ankle.

Osteochondritis dissecans is a condition of the subchondral bone, with secondary effects on the articular cartilage. It most commonly affects the knee, elbow, and ankle and is typically seen in young, active populations. Many osteochondritis dissecans lesions are asymptomatic, but more advanced lesions can cause pain, swelling, and mechanical symptoms. Multiple treatment options have been proposed, including nonsurgical and surgical approaches. It is important to be aware of the epidemiology, presenting symptoms, and indications for nonsurgical and surgical treatment options for osteochondritis dissecans of the knee, elbow, and ankle.

Is there value in the routine practice of discarding the incision scalpel from the surgical field to prevent deep wound contamination with Cutibacterium acnes?

BACKGROUND: Cutibacterium acnes is found in skin flora of the shoulder and is the most common microbe identified in periprosthetic shoulder infections. The purpose of this study is to determine if there is C acnes present on the incision scalpel in patients undergoing shoulder arthroplasty despite extensive skin preparation techniques to prevent wound contamination. METHODS: The authors collected a consecutive case series of patients meeting inclusion criteria. Patients were included if they underwent either primary or revision shoulder arthroplasty at the tertiary care hospital with the senior author during the study period. Culture swab samples, testing for presence of C acnes, were collected from 17 consecutive patients who underwent shoulder arthroplasty with a single fellowship-trained surgeon between November 2019 and March 2020. Culture reports were recorded as "positive" or "negative" after 21 days. Institutional review board approval of the study protocol was obtained. The null hypothesis was that there would be no cases with knife blades "culture positive" for C acnes. RESULTS: 17 patients were identified and fit inclusion criteria. There were 12 men (mean age 64.3 years, range 48-79 years) and 5 women (mean age 69.8 years, range 59-79 years). Two patients (11.8%) were found to have C acnes growth on the skin knife. Both patients were male and older than 70 years undergoing primary reverse shoulder arthroplasty with no history of previous shoulder infections. CONCLUSION: The presence of C acnes on the skin blade in 2 patients validates concerns that there is C acnes present in dermal tissue despite extensive attention to eradication of these microbes. There was a high rate of C acnes contamination on scalpel blades used for initial skin incisions and the authors conclude that there is value in discarding these blades from the surgical field.

Fundamental Studies of the Singlet Oxygen Reactions with the Potent Marine Toxin Domoic Acid.

Domoic acid (DA), a potent marine toxin, is readily oxidized upon reaction with singlet oxygen (1O2). Detailed product studies revealed that the major singlet oxygenation reaction pathways were the [2 + 2] cycloaddition (60.2%) and ene reactions (39.8%) occurring at the Z double bond. Diene isomerization and [4 + 2] cycloaddition, common for conjugated diene systems, were not observed during the singlet oxygenation of DA. The bimolecular rate constant for the DA reaction with 1O2 determined by competition kinetics was 5.1 × 105 M-1 s-1. Based on the rate constant and steady-state concentrations of 1O2 in surface waters, the environmental half-life of DA due to singlet oxygen-induced transformations is between 5 and 63 days. The 1O2 reaction product mixture of DA did not exhibit significant biological activity based on ELISA studies, indicating that singlet oxygenation could be an important natural detoxification process. The characteristic oxidation products can provide valuable markers for the risk assessment of DA-contaminated natural waters.

Indications for Arthroscopic Subacromial Decompression. A Level V Evidence Clinical Guideline.

Since the introduction of acromioplasty by Neer in 1971 and arthroscopic subacromial decompression (SAD) by Ellman in 1987, the outcomes have been reported to be consistently good. Recently it was suggested that supervised physical therapy is comparable with SAD, which was contested by other studies claiming that SAD is clearly superior to nonoperative treatment. Before consideration for treatment, the diagnosis of impingement with an intact rotator cuff must be determined by clinical history, a detailed and structured clinical examination, and appropriate imaging. In favor of SAD are published long-term studies with a minimum of 10 years outlining significant functional and clinical improvement. The main factor for failure reported was workers compensation, calcific tendinopathy, and high-grade partial-thickness tears. Studies nonsupportive of SAD suffer from bias, crossover from the nonoperative group to the operative group following failure of conservative treatment, and loss of follow-up. Recently, lateral acromion resection has been suggested as a viable alternative, effectively reducing the critical shoulder angle. Following nonoperative treatment for at least 6 weeks, SAD is a viable and good surgical option for the treatment of shoulder impingement with an intact rotator cuff. Care should be taken to avoid resection of the acromioclavicular ligament. Five millimeters of lateral acromion resection is the recommended amount of resection. Patients with chronic calcific tendinitis, workers compensation, and partial-thickness tears should not be treated by SAD alone.

Degenerative Meniscus Lesions: An Expert Consensus Statement Using the Modified Delphi Technique.

PURPOSE: The purpose of this study was to perform an evidence-based, expert consensus survey using the Delphi panel methodology to develop recommendations for the treatment of degenerative meniscus tears. METHODS: Twenty panel members were asked to respond to 10 open-ended questions in rounds 1 and 2. The results of the first 2 rounds served to develop a Likert-style questionnaire for round 3. In round 4, the panel members outside consensus were contacted and asked to either change their score in view of the group's response or argue their case. The level of agreement for round 4 was defined as 80%. RESULTS: There was 100% agreement on the following items: insidious onset, physiological part of aging, tears often multiplanar, not all tears cause symptoms, outcomes depend on degree of osteoarthritis, obesity is a predictor of poor outcome, and younger patients (<50 years) have better outcomes. There was between 90% and 100% agreement on the following items: tears are nontraumatic, radiographs should be weightbearing, initial treatment should be conservative, platelet-rich plasma is not a good option, repairable and peripheral tears should be repaired, microfracture is not a good option for chondral defects, the majority of patients obtain significant improvement and decrease in pain with surgery but results are variable, short-term symptoms have better outcomes, and malalignment and root tears have poor outcomes. CONCLUSIONS: This consensus statement agreed that degenerative meniscus tears are a normal part of aging. Not all tears cause symptoms and, when symptomatic, they should initially be treated nonoperatively. Repairable tears should be repaired. The outcome of arthroscopic partial meniscectomy depends on the degree of osteoarthritis, the character of the meniscus lesion, the degree of loss of joint space, the amount of malalignment, and obesity. The majority of patients had significant improvement, but younger patients and patients with short-term symptoms have better outcomes. LEVEL OF EVIDENCE: Level V - expert opinion.

Strategies and Tools to Enhance Patient Safety: HROs, HEROs, and Safety Culture.

INTRODUCTION: The Institute of Medicine has defined multiple domains to improve safety, efficiency, and effectiveness of health care. High-Reliability Organizations (HROs) address these issues and promote safety/reliability at the highest level. METHODS: HROs create a bottom-up, top-down culture that focuses upon continuous improvement by withholding blame on individuals yet requiring all members to be accountable for continuous improvement. RESULTS: Supporting staff to speak up, identify, and engage on the path to perfect care and zero harm are elements of a safety culture. In addition to safety, HROs can also focus on effectiveness and efficiency. This may be accomplished by creating consistent care practices that reduce irrational variation, decrease complexity, and lower risk. DISCUSSION: Developing a culture focused upon reliability, safety, and staff resilience is critical for HROs. HROs support and empower all staff to be vigilant and report concerns about any issue related to safety and support the development of a "Safety Culture." HROs focus upon safety will be enhanced by an expanded focus upon effectiveness and efficiency to improve value. A focus on standard clinical practices and clinician integration into the supply chain will help organizations produce better value and be an essential tool to reduce complexity and risk within health care systems.